After a week of live episodes to celebrate the 30th anniversary of EastEnders, the 'Who Killed Lucy?' storyline came to an emotional end.

Bobby Beale was revealed as the killer on Thursday night, though Jane tried to take the blame for her murder when finally confronted by Ian.

But the tearful father realised his new wife was protecting his youngest son, and decided to protect their murderous secret anyway - as Bobby doesn't even realise he killed his sister.

Tragic truth: Ian Beale discovers his son Bobby killed Lucy in the finale of the EastEnders live week

Show boss Dominic Treadwell-Collins said: 'He thinks she got up and walked out the door, and that is what Jane has said to him.'

The producer said he initially had two other suspects in mind for the murder before deciding to put Bobby in the frame and added the idea had been partly inspired by the murder mystery novels of Agatha Christie.

Final words: Ian kissed the last letter of love written by Lucy on the night she died

Then it dawns on him: 'He called his mum. He did something bad and he phoned you for help.'

'The door was open, she was lying there,' Jane cries, 'I thought it was joke. I checked her breathing, there was nothing. He said she started it, but he didn't seem to know she was dead. He hit her with a box.'

'The jewellery box, he gave that to Beth for Christmas,' Cindy Williams (Mimi Keene) says shocked.

'He's a 10-year old boy, why did he do such a thing,' Ian laments.

Apology: Lucy's letter was away of saying sorry for the trouble she had caused her father

'He said he heard the arguing that night, he couldn't sleep. He said she was writing something, he wanted her to stop causing trouble. He picked up the box, she fell, he couldn't wake her, he said he tried all on his own and that's when he called me,' Jane cries.

Peter still didn't understand why Jane tried to cover it up and Jane continues to play the loving mother card to justify her actions to protect her son.

Ian runs out the room to be sick when he hears that his wife put her into the boot of the car and carried her 'like a child' into the woods before laying her down and crying her sorrys to her dead step-daughter.

Maternal instinct: Jane said she wanted to protect her son that's why she disposed of Lucy's body in Walford Common

She continues to try and justify Bobby's actions: 'He was frustrated, he just wanted to make things better.'

Then Phil Mitchell (Steve McFadden) turns up to tell Ian about his mother Kathy (Gillian Taylforth) actually being alive but the distraught father frantically tells him to leave.

'Is everything alright?' Bobby says as he arrives home, unaware that he even killed Lucy with his actions.

Can't believe it: Peter doesn't want to continue the lie after finding out the truth about his twin sister's death

'If the truth comes out we're all going to get the blame,' Peter says.

Jane and Cindy both say they should keep quiet, while Ian goes up to speak to his son. Beale than tells Peter that they must continue to cover up the murder.

'I won't be part of it,' Peter says. 'Nine hours she was laying there in the cold. The only people you care about is Jane and Bobby.'

'She treated her like a sack of rubbish,' Peter screams and tells Ian 'he'll never forgive him'.

Angry: Peter gets aggressive with Jane as she tries to persuade the family to keep the secret

Peter runs out the house leaving Jane and Ian to reconcile over their decision to not got to the police with the truth.

Bobby also hands Cindy the final note written by Lucy which Jane referred to in her confession.

Too upset to read it, Cindy takes it upon herself to recite the final words.

'Dear Dad I'm sorry for what I said earlier. i didn't mean it, i'm a wreck but i'm going to change starting tonight,' she says.

The omen: Ian speaks to Bobby, who doesn't actually know that he killed Lucy

'Look at me home before midnight and the drugs are gone. When you get home look in on me I'll be sleeping.

'But wake me up I want to tell you how much you mean to me and how much I love you don't forget dad wake me up, Lucy Lou.'

Ian breaks down in tears as he kissed the final words of his dead daughter.

Sticking together: Jane and Ian put on a united front for the sake of their son

'There's a body,' she tells the detective dealing with Nick Cotton's death. They think she's talking about the nasty villain not Dean and Mick quickly pulls her away.

Inside the pub, Linda (Kellie Bright) asks him to marry her in front of everyone but he tells her 'not now' as Nancy drags him upstairs.

'What's a matter with me, course I'll marry ya,' he says turning back and snogging his partner.

But as they return to the cellar, Dean's body is miraculously gone.

Keep it quiet: Mick Carter gets his daughter Nancy to not go to the police about Dean Wick's lifeless body in the Queen Vic cellar

At the end of the episode, fireworks light up the Square to celebrate the Carters' engagement.

'You alright?' Mick asks Ian.

'We will be,' he replies, with Phil solemnly watching the pair before walking away himself.

Since Lucy was found dead last April, the soap has seen alibis disproven, motives revealed, and suspects brought into the frame, including her father Ian.

Gone: They discover his body has vanished from the cellar, with everyone else none the wiser to the incident

The mystery unravelled in this week's EastEnders Live Week, which saw more than one million extra viewers tune in.

The 'Live Week' saw regular EastEnders' episodes, airing on Tuesday, Wednesday and Thursday, interspersed with live scenes. Tonight's episode will be the only completely live episode of the week.

More than 9.6million viewers - a two-year high for the BBC One soap - watched the show as it first went live on Tuesday. It means the episode attracted 1.5million more viewers than last Tuesday's episode.

Tough night: Both Mick and Ian head out to the Square after a rather stressful evening

Viewing figures dipped for Wednesday's instalment but 8.9million people still tuned in.

The high viewing figures will no doubt please the show's bosses, who chose to wait almost a year – until the soap's 30th anniversary – to bring the dramatic whodunnit to a close.

An average of more than 10million people are thought to have tuned in last night to watch the conclusion to the long-standing storyline.

Unaware: Phil Mitchell tried to tell Ian about his mum Kathy being alive but doesn't get a chance

And, as the killer was revealed to be schoolboy Bobby, fans were sent into a frenzy on Twitter with more 30,000 tweets alone sent in the single minute after the killer was revealed.

Figures showed that more than one million tweets were sent in total during the two EastEnders' episodes which aired last night, making them the most tweeted-about episodes of a soap ever.

The second episode eclipsed the 508,678 messages sent during the first special by more than 10,000, with 519,359 tweets posted as the killer came closer to being unmasked, data from social analytics firm Kantar Social TV UK showed.

Happy ending: Fireworks were set off to mark the engagement of Mick and Linda and the end of EastEnders Live Week